The first three cases at each institution (baseline and at least one follow-up) will be performed under the guidance of at least one of the study PIs to ensure standardization amongst all three sites. The ultrasound examinations will be performed by a qualified sonographer. Efforts will be made to have all CEUS scans performed by the same dedicated sonographer, enabling us to evaluate operator dependence. During the ultrasound examination, the patient will be asked to lie in the supine position and a 20-22 gauge cannula will be placed in a superficial vein (preferably an antecubital vein). Ultrasound imaging will be performed using a state of the art Logiq E9 scanner with C1-5-D broad-spectrum convex transducer and a RAB2-5-D broad-spectrum real-time 4D transducer (GE Healthcare, Wauwatosa, WI). As part of this study, the investigators have budgeted for the purchase of 3 4D probes (not routinely available in clinical practice) and the installation of GE's ultrasound volumetric and contrast imaging packages that provide 2D and 4D CEUS capabilities. In the event the patient has multiple lesions scheduled for treatment, up to 2 lesions will be imaged independently on CEUS. Patients will first undergo 2D baseline imaging. B-mode measurements and sweeps of the lesion in the transverse and sagittal planes will be performed, followed by standard power Doppler imaging (PDI). Following baseline imaging, patients will receive a bolus IV injection of up to 0.6 ml of Definity, followed by a 10 cc saline flush. Since Definity is currently only approved for echocardiography, the investigators have applied to the FDA for an investigational new drug application for CEUS evaluation of TACE.